v3.26.1
REPORTABLE SEGMENT DATA - RECONCILIATION OF SEGMENT INCOME TO CONSOLIDATED (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Mar. 31, 2026
Mar. 31, 2025
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments $ 939,401   $ 913,027   $ 1,544,255 $ 1,401,388
Corporate and other 641,350   569,199   1,082,249 928,152
Operation and maintenance 112,496   111,041   199,177 199,673
Regulatory rider expenses 59,450   48,501   92,604 70,977
Depreciation and amortization 50,129   47,967   99,705 93,296
Gain on sale of assets 0   (688)   0 (55,547)
Interest expense, net of capitalized interest 34,975   32,527   70,651 66,418
Income tax provision 66,176   61,593   100,401 98,977
Equity in earnings of affiliates 2,741   1,452   4,564 2,852
Total net income 218,912 $ 122,490 204,287 $ 131,319 341,402 335,606
ES            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 4,900   4,900   9,900 9,900
Corporate and other            
Segment Reporting Information [Line Items]            
Corporate and other 14,720   14,718   30,489 29,972
Total net income (1,821)   79   (710) 438
Operating Segments            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 924,443   898,004   1,513,291 1,370,732
Natural gas purchases 416,966   427,204   673,838 625,357
Operation and maintenance 98,256   96,079   170,235 170,687
Regulatory rider expenses 59,450   48,501   92,604 70,977
Depreciation and amortization 49,842   47,817   99,140 92,869
Gain on sale of assets     (688)     (55,547)
Interest income 2,671   3,095   5,575 6,222
Other segment income (expense) 15,694   14,827   26,340 24,364
Interest expense, net of capitalized interest 35,924   32,275   72,573 65,957
Income tax provision 64,157   61,996   98,701 98,656
Equity in earnings of affiliates 2,282   1,161   3,522 2,122
Net income attributable to reportable segments 220,733   204,208   342,112 335,168
Operating Segments | NJNG            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 640,922   618,339   1,050,823 951,767
Corporate and other 574,584   509,145   949,205 805,210
Natural gas purchases 276,567   275,298   447,291 405,303
Operation and maintenance 65,715   61,257   114,703 113,351
Regulatory rider expenses 59,450   48,501   92,604 70,977
Depreciation and amortization 37,509   35,713   74,469 67,797
Gain on sale of assets     0     0
Interest income 648   610   1,373 1,247
Other segment income (expense) 6,803   6,534   12,126 11,414
Interest expense, net of capitalized interest 19,180   17,259   38,479 34,713
Income tax provision 41,677   43,230   64,909 61,491
Equity in earnings of affiliates 0   0   0 0
Net income attributable to reportable segments 148,513   144,531   232,342 211,439
Operating Segments | CEV            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 9,932   7,967   41,692 34,373
Corporate and other 8,883   7,833   18,235 16,555
Natural gas purchases 0   0   0 0
Operation and maintenance 10,549   10,704   19,889 21,270
Regulatory rider expenses 0   0   0 0
Depreciation and amortization 7,121   5,504   14,153 11,929
Gain on sale of assets     (688)     (55,547)
Interest income 0   250   31 250
Other segment income (expense) 8,859   8,203   14,134 12,574
Interest expense, net of capitalized interest 8,172   5,937   16,538 12,311
Income tax provision (1,828)   (1,079)   910 13,062
Equity in earnings of affiliates 0   0   0 0
Net income attributable to reportable segments (5,223)   (3,958)   4,367 44,172
Operating Segments | ES            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 244,155   246,390   363,262 332,698
Corporate and other 13,491   11,890   26,331 23,837
Natural gas purchases 139,938   151,847   225,712 219,715
Operation and maintenance 9,770   11,208   12,955 13,073
Regulatory rider expenses 0   0   0 0
Depreciation and amortization 43   62   84 109
Gain on sale of assets     0     0
Interest income 21   39   60 73
Other segment income (expense) 171   353   341 703
Interest expense, net of capitalized interest 3,124   3,262   6,542 7,147
Income tax provision 21,737   19,111   28,038 21,880
Equity in earnings of affiliates 0   0   0 0
Net income attributable to reportable segments 69,735   61,292   90,332 71,550
Operating Segments | S&T            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 29,434   25,308   57,514 51,894
Corporate and other 29,434   25,308   57,514 51,894
Natural gas purchases 461   59   835 339
Operation and maintenance 12,222   12,910   22,688 22,993
Regulatory rider expenses 0   0   0 0
Depreciation and amortization 5,169   6,538   10,434 13,034
Gain on sale of assets     0     0
Interest income 2,002   2,196   4,111 4,652
Other segment income (expense) (139)   (263)   (261) (327)
Interest expense, net of capitalized interest 5,448   5,817   11,014 11,786
Income tax provision 2,571   734   4,844 2,223
Equity in earnings of affiliates 2,282   1,161   3,522 2,122
Net income attributable to reportable segments 7,708   2,343   15,071 8,007
Intersegment Eliminations            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 238   305   475 684
Intersegment Eliminations | NJNG            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 238   306   475 643
Intersegment Eliminations | CEV            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 0   0   0 0
Intersegment Eliminations | ES            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments 0   0   0 0
Intersegment Eliminations | S&T            
Segment Reporting Information [Line Items]            
Operating revenues attributable to reportable segments $ 0   $ (1)   $ 0 $ 41